Fujian Li, Yuqi Shan, Ming Li, Yakun Guo, Chao Liu
{"title":"Insights for River Restoration: The Impacts of Vegetation Canopy Length and Canopy Discontinuity on Riverbed Evolution","authors":"Fujian Li, Yuqi Shan, Ming Li, Yakun Guo, Chao Liu","doi":"10.1029/2023wr036473","DOIUrl":null,"url":null,"abstract":"River restoration projects often involve vegetation planting to retain sediment and stabilize riverbanks. Laboratory experiments have explored the impact of rigid emergent vegetation canopies on bed morphology. Inside canopies, bed erosion is attributed to vegetation-induced turbulent kinetic energy (<i>TKE</i>). Based on the in-canopy local <i>TKE</i> and the criteria for sediment movement, a method is established and validated for predicting the length of the bed erosion region. In the bare channel, bed erosion is related to the ratio of canopy length to flow adjustment distance, <i>L</i>/<i>L</i><sub><i>I</i></sub>, and exhibits two trends. At <i>L</i>/<i>L</i><sub><i>I</i></sub> < 1, the maximum depth, <i>d</i><sub><i>s</i>(<i>bare</i>)</sub>, and length, <i>L</i><sub><i>s</i>(<i>bare</i>)</sub>, of the bed erosion region increase with increasing canopy length. At <i>L</i>/<i>L</i><sub><i>I</i></sub> ≥ 1, <i>d</i><sub><i>s</i>(<i>bare</i>)</sub> and <i>L</i><sub><i>s</i>(<i>bare</i>)</sub> are not influenced by the canopy length and remain constant. In vegetated regions with the same length and plant density, discontinuous canopies (streamwise interval <i>s</i> ≥ canopy width <i>D</i>) yield weaker bed erosion than continuous canopies. The mutual influence between two canopies must be considered if the canopy interval satisfies <i>s</i> < 3<i>D</i>. These results provide insights for designing vegetation canopies for river restoration projects.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":null,"pages":null},"PeriodicalIF":4.6000,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Resources Research","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1029/2023wr036473","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
River restoration projects often involve vegetation planting to retain sediment and stabilize riverbanks. Laboratory experiments have explored the impact of rigid emergent vegetation canopies on bed morphology. Inside canopies, bed erosion is attributed to vegetation-induced turbulent kinetic energy (TKE). Based on the in-canopy local TKE and the criteria for sediment movement, a method is established and validated for predicting the length of the bed erosion region. In the bare channel, bed erosion is related to the ratio of canopy length to flow adjustment distance, L/LI, and exhibits two trends. At L/LI < 1, the maximum depth, ds(bare), and length, Ls(bare), of the bed erosion region increase with increasing canopy length. At L/LI ≥ 1, ds(bare) and Ls(bare) are not influenced by the canopy length and remain constant. In vegetated regions with the same length and plant density, discontinuous canopies (streamwise interval s ≥ canopy width D) yield weaker bed erosion than continuous canopies. The mutual influence between two canopies must be considered if the canopy interval satisfies s < 3D. These results provide insights for designing vegetation canopies for river restoration projects.
期刊介绍:
Water Resources Research (WRR) is an interdisciplinary journal that focuses on hydrology and water resources. It publishes original research in the natural and social sciences of water. It emphasizes the role of water in the Earth system, including physical, chemical, biological, and ecological processes in water resources research and management, including social, policy, and public health implications. It encompasses observational, experimental, theoretical, analytical, numerical, and data-driven approaches that advance the science of water and its management. Submissions are evaluated for their novelty, accuracy, significance, and broader implications of the findings.